Active research and development work have been conventionally performed on compounds containing heteroatoms such as sulfur atoms as monomolecular complexes and self-assembled films on various substrates. To apply these monomolecular complexes and self-assembled films to electronic devices, a great deal of research and development work have also been conducted concerning compounds capable of imparting electrical conductivity to monomolecular complexes and self-assembled films.
In addition, research and development work have also been performed about compounds having the above-described complex-forming and self-assembling function, and also about junctions between compounds obtained by imparting electrical conductivity to such compounds and electrodes composed of metals or semiconductors.
As a conductivity-imparted compound for self-assembled films, for example, there is known 2-(11-mercaptoundecyl)-hydroquinone having a quinone moiety as an electron acceptor structure at an end thereof (see Non-Patent Document 1).
Also known is a mixture of bis(10-(2-(2,5-cyclohexadien-1,4-diylidene)dimalononitrile))decyl)disulfide having a teracyanoquinodimethane moiety as an electron acceptor structure at an end thereof and N,N,N-trimethyl-N-(10-mercapto)decyl-1,4-phenylenediamine having a tetramethylphenylenediamine moiety as an electron donor structure at an end thereof (see Non-Patent Document 2).
Further, compounds represented by the following formula (3) are also known. As specific compounds, there are known compounds of the formula (3) in which R11 to R14 are each a methyl group, 2-cyanoethyl group or a hydrogen atom and compounds of the formula (3) in which R11 is a hydrogen atom and R12 to R14 are each a 2-cyanoethyl group (see Patent Document 1). These compounds are advantageous from the standpoint of industrial applications, as their production processes are simple and easy.
wherein R11 to R14 are each independently a hydrogen atom, a substituted or unsubstituted C1 to C6 alkyl group, a substituted or unsubstituted C2 to C6 alkenyl group, a substituted or unsubstituted C1 to C6 aryl group, a bromine atom, or a chlorine atom.
In addition, compounds represented by the following formula (4) are also known (see Patent Document 2). These compounds are also advantageous from the standpoint of industrial applications, as their production processes are simple and easy.
wherein R1 to R4 each independently represent an organic group, at least one of them represents an organic group, which is a divalent connecting group including at least one of an arylene group and an alkylene group and has at an end thereof a binding group capable of covalently or coordinatively forming a bond with a metal surface, metal oxide surface or semiconductor surface, and R5 to R8 each independently represent a halogen atom, a C1 to C3 alkyl group or a C1 to C3 alkoxy group.
As a process for the fabrication or production of electrodes composed of metals and a semiconductors by making use of various monomolecular complexes or self-assembled films or conductivity-imparted various monomolecular complexes or self-assembled films while taking their applications to electronic devices, for example, so-called molecular wiring or the like is known (see Patent Documents 3 to 7 and Non-Patent Documents 3 to 16).
As disclosed in the respective documents referred to in the above, a variety of compounds have been reported to date as monomolecular conductive complexes or compounds for conductive self-assembled films. However, their chemical structures are considerably limited so that many of them lack versatility and are functionally insufficient. Moreover, their production processes are complex and, when industrial applications to electronic devices and the like are taken into consideration, none of them have practical utility.
Patent Document 1:                WO 01/68595 Pamphlet        
Patent Document 2:                JP-A 2004-175742        
Patent Document 3:                JP-A 2003-168788        
Patent Document 4:                JP-A 2004-058260        
Patent Document 5:                JP-A 2004-119618        
Patent Document 6:                JP-A 2004-136377        
Patent Document 7:                JP-A 2005-033184        
Non-Patent Document 1:                J. Chem. Soc., Faraday Trans., 92, 3813 (1996)        
Non-Patent Document 2:                Langmuir, 14, 5834 (1998)        
Non-Patent Document 3:                Science, 278, 10 Oct., 252 (1997)        
Non-Patent Document 4:                Science, 286, 19 Nov., 1550 (1999)        
Non-Patent Document 5:                Science, 301, 29 Aug., 1221 (2003)        
Non-Patent Document 6:                Applied Physics Letters, 82, 19, 3322 (2003)        
Non-Patent Document 7:                Advanced Materials, 15, 22, 1881 (2003)        
Non-Patent Document 8:                Angew. Chem. Int. Ed., 2004, 43, 6148        
Non-Patent Document 9:                Surface Science, 573, 1 (2004)        
Non-Patent Document 10:                Chem. Mater., 2004, 16, 4477        
Non-Patent Document 11:                Journal of Chemical Physics, 121, 13, 6485 (2004)        
Non-Patent Document 12:                J. Am. Chem. Soc., 2004, 126, 14182        
Non-Patent Document 13:                J. Am. Chem. Soc., 2004, 126, 15897        
Non-Patent Document 14:                Phys. Chem. Chem. Phys., 2004, 6, 4330        
Non-Patent Document 15:                J. Am. Chem. Soc., 2005, 127, 1384        
Non-Patent Document 16:                J. Am. Chem. Soc., 2005, 127, 2386        